#include <iostream>
#include <fstream>
using namespace std;
ifstream f("pairs.in");
ofstream g("pairs.out");
int n, i, j, k = 0, aux1, aux2;

int main()
{
    f >> n;
    int v[n+1];
    for(i = 1; i <= n; i++) {
        f >> v[i];
    }

    for(i = 1; i < n; i++) {
        for(j = i+1; j <= n; j++) {
            if(v[i] != v[j]) {
                if(v[i]%2 != 0 || v[j]%2 != 0) {
                    aux1 = v[i];
                    aux2 = v[j];
                    while(aux1 != aux2) {
                        if(aux1 > aux2)
                            aux1 -= aux2;
                        else aux2 -= aux1;
                    }
                    if(aux1 == 1)
                        k++;
                }
            }
        }
    }

    g << k;
    return 0;
}